The Currant Fruit Fly. 

 TABLE 22. 



221 



Number of Mature Larvae Which Pupated After Being 

 Submerged in Water for a Period of One to Four Days. 



Number Days 



of submerged 

 larvae in water 



Number 

 pupated 



Number 



dead 



pupae 



100 1 

 100 2 

 100 3 

 100 4 



95 



30 



2 







28 



29 



2 







It is evident from these experiments that maggoty fruit or 

 mature larvae when submerged in water for a period of two 

 days failed to give rise to living pupae. Infested currants and 

 gooseberries sorted out during the harvesting of the crop or 

 gathered from the ground could be dumped daily into a pail, 

 barrel or tank of water. The size of the container to be used 

 would depend upon the quantity of drops. When a sufficient 

 amount has accumulated, two days must elapse, after the last 

 addition of infested fruit to the container, before burying or 

 plowing the fruit in the soil. 



Removal of Soil Under Bushes. 



A remedial measure frequently recommended is to remove 

 the surface soil to a depth of one to three inches under the bushes 

 and to deposit it on a road or some other exposed place or to 

 bury it deep. These three different methods were put to experi- 

 mental tests. 



In the first experiment the ground was removed from under 

 12 of 13 currant bushes growing close together in a single row. 

 It was not difficult to work below the shrubs for they were 

 propped up with wooden railings and the earth had been hilled 

 from 7-12 inches above the surrounding substratum. A garden- 

 er's trowel was used to scrape off at least three inches of the 

 surface soil, but difficulty was experienced in removing the dirt 

 beneath the net-work of rootlets. Many of the roots were 

 exposed and some were injured. As soon as a sufficient amount 

 of ground had accumulated, it was loaded on a wheel-barrow, 



